Patella bone plate and methods of fixation

ABSTRACT

A patella fracture fixation system includes a bone plate that is configured to be implanted along an anterior approach. The bone plate has a fixation hub and a plurality of fixation nodes that are connected to the fixation hub. The fixation hub and the fixation nodes can define respective fixation holes. The bone plate can further include legs that are configured to be bent around respective inferior aspects of the patella.

BACKGROUND

Patella fractures represent approximately 1% of all fractures and can bedebilitating injuries resulting in extensor mechanism weakness,decreased knee range of motion, anterior knee pain, and degenerativepatellofemoral arthritis. The limited soft tissue coverage andimportance of the patella in knee extensor mechanism function has madeoperative treatment of these injuries challenging.

Historically, patellar fractures were treated non-operatively, which wasthought to allow for adequate pain relief and partial restoration ofextensor mechanism function. However, as surgical knowledge andtechnique has advanced, management of these injuries has evolved fromnon-operative care or patellectomy to anatomic reduction and internalfixation with a goal of osseous union.

Today, a non-operative treatment course can be recommended fornon-displaced fractures of the patella, particularly when the fractureis non-displaced, the articular surface is not disrupted, and theextensor mechanism is intact. However, a disruption of the articularsurface of as little as 2 mm or separation of bone fragments by aslittle as 3 mm is conventionally associated with an unacceptable risk ofunsuitable bone healing. Additionally, patients with patella fracturesoften have concurrent retinacular tears that can result in fracturedisplacement and disruption of the extensor mechanism. Further, becauseof the important role of the patella in maintaining normal kinematics ofthe knee, operative management is considered to be the treatment ofchoice for patella fractures when patellar bone fragments are displaced,or the articular surface is disrupted.

One construct commonly used for the operative fixation of patellafractures is a tension band. In particular, an anterior tension band isapplied by passing wires or braided cables or sutures behind previouslyimplanted K-wires at the superior and inferior poles, crossing them, andtwisting the ends to create a figure-eight pattern. Further, a wire orbraided cable can be wrapped circumferentially around the patelladirectly on bone at a location anterior to the previously placed wires,and is tightened by twisting. A modification of this technique can beperformed by replacing the K-wires with cannulated screws, such that awire or braided cable or suture can be passed through the cannulatedscrews to create the anterior tension band with a figure-eightconfiguration, followed by application of a cerclage wire directly onthe circumference of the patella.

While tension band constructs are the most common method of fixation,anterior knee pain, failure of the construct, and functional limitationwith tension band fixation have all been reported. Further, thistechnique often fails to address inferior pole comminution commonly seenin fractures of the patella.

More recently, biomechanical studies have shown an advantage to fixationof patella fractures with plating constructs as opposed to tension bandfixation. While various different patella plating constructs in usetoday can achieve satisfactory fracture reductions, the ultimateoutcomes are often ineffective and clinically poor. In particular,despite reliable fracture healing and restoration of the extensormechanisms, outcomes often remain unacceptable with conventiontechniques. A common misconception among surgeons is that patientsrecovering from patella fracture fixation mostly do well. However, thisis likely because patients are not followed long enoughpost-operatively. Anterior knee pain after patellar fracture fixation isa common complaint during daily activity. Potential causes includepatella baja, extensor mechanism malalignment, articular injury andposttraumatic arthritis, painful implants, or avascular necrosis. Thisanterior knee pain leads to limited rehabilitation and functionalimpairment.

Still another surgical option is to perform a partial or totalpatellectomy, though these procedures are typically reserved for extremecases such as open injuries. Patellectomy procedures produce a high riskfor creating patella baja, and bone-to-bone healing is preferred overtendon-to-bone healing. Also, a partial patellectomy procedure is likelyto disrupt the main blood supply to the patella as it enters theinferior pole.

In other instances of an isolated inferior pole fracture that does notinclude the articular surface, fracture repairs are sometimes performedwith what are commonly known as Krackow sutures. In particular, Krackowsutures are placed on the medial and lateral aspects of the patellartendon, and retrograde drill holes are created from the interior pole tothe superior apex of the patella. The sutures are then passed throughthe drill holes and tied over the superior bony edge of the patella.

SUMMARY

In one aspect of the present disclosure, a patella bone plate includes afixation body that, in turn, includes a fixation hub and a plurality offixation nodes. The fixation hub can have an inner surface configured toface the patella bone and an outer surface opposite the inner surface.The fixation hub can define include an array of fixation holes thatextend from the inner surface to the outer surface. The fixation nodescan extend from the fixation hub and can each define a respectivefixation hole. The bone plate can further include at least one leg thatextends out from the body, the at least one leg being deformable andhaving a length sufficient so as to wrap around an inferior rim of thepatella, the at least one leg including at least one fixation hole.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description will be better understood when readin conjunction with the appended drawings, in which there is shown inthe drawings example embodiments for the purposes of illustration. Itshould be understood, however, that the present disclosure is notlimited to the precise arrangements and instrumentalities shown. In thedrawings:

FIG. 1A is a perspective view of a patella fixation system including abone plate and a plurality of bone anchors secured to a fracturedpatella through fixation holes of the bone plate;

FIG. 1B is an exploded perspective view of the patella fixation systemillustrated in FIG. 1A;

FIG. 2A is an enlarged top plane view of a portion of the bone plateillustrated in FIG. 1A, showing one of the fixation holes;

FIG. 2B is a sectional elevation view of the fixation hole illustratedin FIG. 2A with a variable-angle bone screw threadedly purchased thereinin a first angular orientation;

FIG. 2C is a sectional elevation view of the fixation hole illustratedin FIG. 2B, showing the variable-angle bone screw threadedly purchasedtherein in a second angular orientation different than the first angularorientation;

FIG. 3A is a top plan view of the bone plate illustrated in FIG. 1A,shown having a fixation body and fixation legs extending from thefixation body;

FIG. 3B is a bottom plan view of the bone plate illustrated in FIG. 3A;

FIG. 3C is a top perspective view of the bone plate illustrated in FIG.3A;

FIG. 3D is a bottom perspective view of the bone plate illustrated inFIG. 3A;

FIG. 3E is a side elevation view of the bone plate illustrated in FIG.3A;

FIG. 3F is a sectional elevation view of a portion of the bone plateillustrated in FIG. 3A;

FIG. 4A is a top plan view of a bone plate similar to the bone plateillustrated in FIG. 3A, but shown having shorter fixation legs;

FIG. 4B is a bottom plan view of the bone plate illustrated in FIG. 4A.

FIG. 5A is a top plan view of a bone plate similar to the bone plateillustrated in FIG. 3A, but shown without fixation legs in one example.

FIG. 5B is a bottom plan view of the bone plate illustrated in FIG. 5A;

FIG. 6A is a top plan view of a bone plate similar to the bone plateillustrated in FIG. 5A, but showing the fixation body having additionalfixation holes in one example.

FIG. 6B is a bottom plan view of the bone plate illustrated in FIG. 6A;

FIG. 7A is a top plan view of a bone plate similar to the bone plateillustrated in FIG. 6A but shown having shorter fixation legs;

FIG. 7B is a bottom plan view of the bone plate illustrated in FIG. 7A;

FIG. 8A is a top plan view of a bone plate similar to the bone plateillustrated in FIG. 6A, but shown without fixation legs;

FIG. 8B is a bottom plan view of the bone plate illustrated in FIG. 8A;

FIG. 9A is a side elevation view of the patella fixation assemblyillustrated in FIG. 1A, showing a first fixation leg secured to a medialaspect of a fractured patella;

FIG. 9B is another side elevation view of the patella fixation assemblyshowing a second fixation leg secured to a lateral aspect of thefractured patella;

FIG. 9C is a top plan view of the patella fixation assembly showing aninferior fixation leg secured to an inferior pole of the fracturedpatella;

FIG. 9D is a sectional side elevation view of the bone plate asillustrated in FIG. 3F, shown secured to the patella;

FIG. 9E is a top plan view of the patella fixation assembly similar toFIG. 9C, but showing the bone plate with the inferior fixation legremoved;

FIG. 10A is a perspective view of the patella fixation systemillustrated in FIG. 1A, but showing the a bone plate secured to thefractured patella in a different orientation;

FIG. 10B is a perspective view of the patella fixation systemillustrated in FIG. 10A, but showing the a bone plate secured to thefractured patella in a another different orientation;

FIG. 10C is a perspective view of the patella fixation systemillustrated in FIG. 10B, but showing the a bone plate secured to thefractured patella in a still another different orientation; and

FIG. 11 is a perspective view of a bone plate similar to the bone plateillustrated in FIG. 6A, but shown having first and second groups offixation legs.

DETAILED DESCRIPTION

Referring initially to FIGS. 1A-1B, bone plate 20 is configured forfixation to an underlying bone 21. The underlying bone 21 can be definedby the patella bone 23. In particular, the bone plate 20 can beconfigured to be fixed to a fractured patella bone so as to stabilizethe fractured patella so as to promote healing. As will be appreciatedfrom the description below, the bone plate 20 can be configured tostabilize a heavily comminuted fractures of the patella bone. The boneplate 20 can be a titanium bone plate, a stainless steel bone plate, orany alternative suitable biocompatible made as desired that possessesthe requisite strength for patella fixation.

The bone plate 20 can define an inner surface 22 that is designed andconfigured to face the underlying bone 21, and an outer surface 24opposite the inner surface 22. At least a portion of the inner surface22 can further be configured to abut the underlying bone 21. The boneplate 20 can include a fixation body 26 that includes a fixation hub 28that is configured to secure to an anterior aspect of the patella 23.The fixation body 26 can further include at least one fixation node 54such as a plurality of fixation nodes 54 that are disposed radiallyoutward with respect to the fixation hub 28. The inner surface 22 at thefixation body 26 can be concave. Thus, the inner surface 22 at either orboth of the fixation hub 28 and the fixation nodes 54 can be concave. Inone example, the inner surface 22 at the fixation body 26 can besubstantially dome shaped. The term “substantially” as used herein withrespect to sizes and shapes can include any value within 20% of thestated size and shape unless otherwise indicated. In some examples, thebone plate 20 can further include at least one fixation leg 29 thatextends out from the fixation body 26. As will be appreciated from thediscussion below, the fixation legs 29 extend inferiorly from thefixation body 26 when the fixation hub is positioned on the anteriorsurface of the patella 23. A first one of the fixation legs 29 can beconfigured to be secured to an inferior medial aspect of the patella 23.A second one of the fixation legs 29 can be configured to be secured toan inferior lateral aspect of the patella 23. A third one of thefixation legs 29 can be configured to be secured to an inferior pole ofthe patella 23. Thus, the fixation legs 29 can include a middle leg anda pair of outer legs disposed on opposed sides of the middle leg.

The hub 28 can define a plurality of fixation holes 32 that extend fromthe outer surface 24 to the inner surface 22. The fixation holes 32 areconfigured to receive a bone anchor 34 that threadedly purchases withthe patella. In this regard, it should be appreciated that the boneanchor 34 can threadedly purchase with the patella bone or withfractured patellar bone fragments depending on the position of therespective fixation hole 32. Further, the bone anchors 34 can havedifferent lengths as desired. Thus, at least one of the bone anchors 34can be sized to be driven into multiple bone fragments if desired.

A patella fixation system 25 can include the bone plate 20 and at leastone bone anchor 34 that is configured to secure the bone plate 20 to theunderlying bone. In one example, at least one of the fixation holes 32up to all of the fixation holes 32 can be configured as a locking holehaving at least one thread 36 that is configured to threadedly purchasewith the bone anchor 34 when the bone anchor is driven into the fixationhole 32.

In one example, the bone anchors 34 can include an anchor head 38 and ashaft 40 that extends from the anchor head 38 along a central anchoraxis 39. The shaft 40 can be threaded along a portion of its length upto an entirety of its length, for instance when the bone anchor 34 isprovided as a screw. Thus, rotation of the bone anchor 34 in a firstdirection while the shaft 40 is purchased in the underlying bone cancause the shaft 40 to drive into the underlying bone 21. Conversely,rotation of the bone anchor 34 in a second direction opposite the firstdirection while the shaft 40 is purchased in the underlying bone cancause the shaft 40 to be removed from the underlying bone 21. In anotherexample, the shaft 40 can be smooth along its length, for instance whenthe bone anchor 34 is configured as a nail, rivet, or pin. In oneexample, the anchor head 38 can be configured as a locking head wherebyan external surface of the anchor head 38 is threaded. The anchor head38 is configured to threadedly purchase with the bone plate 20 in thefixation hole 32. The fixation hole 32 extends along a central hole axis33 from the outer surface 24 to the inner surface 22.

Referring now also to FIGS. 2A-2C, the fixation hole 32 can beconfigured as a variable angle fixation hole whereby the anchor head 38is configured to threadedly purchase with the bone plate 20 in thefixation hole 32 when the central anchor axis 39 and the central holeaxis 33 define any angle therebetween within a predetermined range ofangles whereby the shaft 40 is driven into the underlying bone 21.Accordingly, the angle defined by the central anchor axis 39 and thecentral hole axis 33 is adjustable within the range of angles, such thatthe central anchor axis 39 is angularly offset with respect to thecentral hole axis 33 at any angle as desired within the range of angles.In one example, the bone anchor 34 can be inserted into the fixationhole 32 such that the central anchor axis 39 is coaxial with the centralhole axis 33 or at any angle relative to the central hole axis 33 withinthe range of angles. The range of angles can be between and include 0degrees and 15 degrees. The outer surface of the anchor head 38 can beround or substantially spherical as illustrated in FIGS. 3E-F, orsubstantially conically shaped or alternatively shaped as desired.

In accordance with the illustrated example, the fixation hole 32 can bedefined by an interior surface 42 that extends from the outer surface 24to the inner surface 22. The fixation hole 32 can be configured as avariable-angle locking hole in one example. Thus, the interior surface42 can include a plurality of scalloped portions 44, which can beunthreaded, that extend into the interior surface and interrupt the atleast one thread 36. Accordingly, the scalloped portions 44 separate theat least one thread 36 into a corresponding plurality of columns 46 ofthread segments 37 that are spaced from each other, such that ones ofthe scalloped portions 44 are disposed between adjacent ones of thecolumns 46 along a circumferential direction about the central hole axis33. In one example, the fixation hole 32 can include three scallopedportions 44, four scalloped portions 44, or any suitable alternativenumber of scalloped portions 44 as desired. Each of the scallopedportions 44, the columns 46, and the anchor head 38 can be shapedsubstantially as described in U.S. Pat. No. 8,343,196, the disclosure ofwhich is hereby incorporated by reference as if set forth herein.

The thread segments 37 can be defined by any number of threads 36 asdesired. The threads 36 can be adapted and configured to engage externalthreads 41 of the anchor head 38 and can extend along paths which, ifcontinued across the gaps defined by the scalloped portions 44, wouldform a helical threading with a substantially constant pitchcorresponding to the external threads 41 of the anchor head 38. Theanchor head 38 can have an externally spherical shape that allows theexternal threads 41 to threadedly purchase with the thread segments 37whether the bone anchor 34 is inserted co-axially with the central holeaxis 33 as shown in FIG. 2B, or angularly offset from the central holeaxis 33 within the range of angles, as shown in FIG. 2C.

The columns 46 can have any suitable shape as desired. In accordancewith one example, the fixation hole can have a complex shape including afirst portion 47 a that tapers radially inward toward the central holeaxis 33 from the outer surface 24 toward the inner surface 22, and asecond portion 47 b that tapers radially outward away from the centralhole axis 33 from the first portion 47 a to the inner surface 22 of thebone plate 20. The first and second portions 47 a and 47 b can beunthreaded. The first portions 47 a can be arranged along a firstsubstantially conical shape centered on the central hole axis 33, andthe second portions 47 b can be arranged along a second substantiallyconical shape centered on the central hole axis 33. The scallopedportions 44 between the columns 46 can be, for example, substantiallycylindrically shaped and extend radially outward beyond the first andsecond conical shapes, thereby extending the range of angulation of thebone anchor 34 when the bone anchor 34 is inserted into the fixationhole 32, for instance when the shaft 40 extends into one of thescalloped portions 44.

In accordance with the illustrated embodiment, the fixation hole 32 caninclude four columns 46 of thread segments 37 that are spaced about thecircumference of the fixation hole 32. For instance, columns 46 ofthread segments 37 can be spaced substantially equidistantly from oneanother about the circumference of the fixation hole 32. Thus, thescalloped portions 44 can define widths measured circumferentially aboutthe central hole axis 33 that are substantially equal to one another. Itshould be appreciated, however, that the fixation hole 32 can includeany number of columns 46 arranged in any number of patterns as desired.Furthermore, it should be appreciated that the columns 46 canalternatively be spaced about the circumference of the fixation hole 32by varying distances, and the columns 46 and scalloped portions 44 canhave different circumferential widths as well.

While one or more of the fixation holes 32 up to all of the fixationhole 32 can be configured as a variable angle locking hole in the mannerdescribed above, it should be appreciated that one or more of thefixation holes 32 up to all of the fixation holes 32 can bealternatively constructed as desired. For instance, at least one of thefixation holes 32 can be configured as a standard-type fixed anglelocking hole. In particular, the bone plate 20 is configured tothreadedly mate with the anchor head 38 in the fixation hole 32 onlywhen the bone anchor 34 is oriented at a predetermined orientation withrespect to the central hole axis 33. In this example, the thread 36 canextend continuously along its respective helical path along multiplerevolutions about the central hole axis 33 so as to purchase with theanchor head 38. The predetermined orientation can be a nominalorientation whereby the central anchor axis 39 is coincident with thecentral hole axis 33. Alternatively, the predetermined orientation canbe defined when the central anchor axis 39 is oriented oblique to thecentral hole axis 33. In certain examples, the anchor head 38 can beconfigured to threadedly mate with the bone plate 20 in the fixationhole 32 only when the bone anchor 34 is oriented at the predeterminedorientation.

Alternatively or additionally still, at least one of the fixation holes32 up to all of the fixation holes 32 can be configured as an unthreadedcompression hole. Thus, one or more of the bone anchors 34 can beconfigured as a compression anchor whose anchor head 38 defines acompression head that is configured to bear against the bone plate 20 inthe compression hole so as to apply a compressive force against the boneplate 20 toward or against the underlying bone. The interior surface 42can extend between the outer surface 24 and the inner surface 22 so asto at least partially define the fixation hole 32. During operation, theshaft 40 of the bone anchor 34 can be inserted through the fixation hole32 and driven into the underlying bone 21. When at least a portion ofthe shaft 40 is threaded, rotation of the bone anchor 34 causes theanchor head 38 to compress against the interior surface 42. As a result,the anchor head 38 causes the bone plate 20 to apply a compressive forceagainst the underlying bone 21. The external surface of the anchor head38 can be unthreaded. Similarly, at least a portion up to an entirety ofthe interior surface 42 that abuts the unthreaded external surface ofthe anchor head 38 can be unthreaded.

Alternatively or additionally still, at least one other ones of thefixation holes 32 can be a combination hole, whereby a threaded lockinghole portion and an unthreaded compression hole portion intersect eachother to define the combination hole. The bone anchor 34 can beselectively driven into the threaded locking hole portion and theunthreaded compression hole portion. The threaded locking hole portioncan define a variable angle locking hole portion or a standard typelocking hole portion as desired.

Referring now to FIGS. 3A-3D, and as described above, the fixation body26 of the bone plate 20 can include the fixation hub 28 and the at leastone fixation node 54 that is disposed radially out with respect to thefixation hub 28. The bone plate 20 can be preformed such that the innersurface 22 at the fixation body 26 can define a concavity. Thus, theouter surface 24 at the fixation body 26 can be convex. In one example,the inner surface at the fixation body 26 can be substantially domeshaped. Thus, the bone plate 20 as-manufactured can generally conform tothe patella bone 23. In one example, the dome shape of the inner surface22 at the fixation body 26 can be defined by any suitable radius asdesired. For instance, the radius can in a range from approximately 25mm to approximately 75 mm. In one example, the range can be fromapproximately 40 mm to approximately 60 mm. In particular, the radiuscan be approximately 50 mm. It should be appreciated that the concavityof the inner surface 22 can define any suitable geometry as desiredother than a dome. During operation, the inner surface 22 is morepreformed to the outer surface of the patella 23 (see FIG. 1A) thanconventional flat bone plates. It is envisioned that in somecircumstances the fixation body 26 may be manipulated in situ to betterconfirm to the patella 23. In this regard, it should be appreciated thatthe fixation body 26 can be flexible and deformable so as to conform thefixation plate 20 to the underlying bone 21.

Referring now to FIGS. 3A-3B, the fixation hub 28 is configured to besecured to one or more bone fragments of the patella 23 as desired. Thefixation hub 28 can define a geometric center 48 that defines a centralhub axis 35. The fixation hub 28 can define a fixation hole 32 at thegeometric center 48. The central hole axis 33 of the fixation hole 32 atthe geometric center 48 can be coincident with the central hub axis 35.Thus, reference to the central hole axis 33 of the fixation hole at thegeometric center 48 can apply more generally to the central hub axis 35whether or not the geometric center defines a fixation hole 32.

The fixation hub 28 can further include an array 50 of fixation holes32. The array 50 can be a circumferential array. The fixation holes 32of the array 50 can be arranged along a path that extends about thegeometric center 48. For instance, the path can be a closed path thatsurrounds the geometric center 48. In one example, the path of the array50 can define a circle. The central hub axis 35 can define the center ofthe circle. The central hole axes 33 (see FIG. 2B) can lie on thecircle. In one example, the fixation holes 32 can be spacedequidistantly from each other along the circle. Alternatively, thefixation holes 32 can be spaced at variable distances from each other.Further, while the fixation holes 32 of the array 50 can be arranged onthe circular path, it should be appreciated that the fixation holes 32of the array 50 can be alternatively arranged as desired. For instance,the fixation holes 32 of the array 50 can lie on any curved path. Thecurved path can define an ellipse in one example. Alternatively, thepath can define a polygon. For instance, the central hole axes 33 candefine the vertices, respectively, of the polygon. In one example, asillustrated in FIGS. 3A-3B, the polygon can be a regular polygon.Alternatively, the polygon can be an irregular polygon. In this regard,it should be appreciated that the fixation body 26 can be symmetrical orasymmetrical as desired.

In one example, the array 50 can include six fixation holes 32. Thus,the regular polygon can be configured as a hexagon. It should beappreciated, however, that the array 50 can include any number offixation holes 32 as desired. In one example, the fixation hole 32 atthe geometric center 48 and the fixation holes 32 of the array 50 canconstitute all fixation holes 32 of the fixation hub 28. Alternatively,the fixation hub 28 can include at least one additional fixation hole 32in addition to the fixation hole 32 at the geometric center 48 and thefixation holes 32 of the array 50. The at least one additional fixationhole 32 can be disposed between the geometric center 48 and the array50. Alternatively or additionally, the at least one additional fixationhole 32 can be disposed radially outward of the array 50. Thus, thearray 50 can be disposed between the at least one additional fixationhole 32 and the geometric center 48.

The fixation body 26 can include at least one aperture 52 that extendsthrough the fixation hub 28 from the outer surface 24 to the innersurface 22. For instance, the fixation body 26 can include a pluralityof apertures 52 that extend through the fixation hub 28 from the outersurface 24 to the inner surface 22. The fixation body 26 can include anynumber of apertures 52 as desired. Further, the apertures 52 can be ofany suitable size and shape as desired. Further still, the apertures 52can be positioned at any location as desired. In one example, theapertures 52 can be elongate. For instance, the apertures 52 can beelongate along a respective central axis 59. The central axes 59 of theapertures 52 can define tangents along a respective common circle thatsurrounds the geometric center 48 of the fixation hub 28. Further, thegeometric center of the apertures 52 can lie on the respective circle.Thus, the geometric centers of the apertures 52 can be circumferentiallyaligned with each other. For instance the geometric center 48 of thefixation hub 28 can define the center of the respective circle. Thus,the respective circle of the apertures 52 can be concentric with thecircle defined by the path of the array 50 of fixation holes 32. Therespective circle of the apertures 52 can define an inner circle of thefixation hub 28. The circle of the array 50 of fixation holes 32 candefine an outer circle of the fixation hub 28 that surrounds the innercircle of the fixation hub 28.

The geometric centers of the apertures 52 can be radially aligned witheach of the fixation hole 32 at the geometric center 48 and an alignedone 32 a of the fixation holes 32 of the array 50, with respect to a topplan view of the bone plate. For instance, the geometric centers of theapertures 52 can lie on a respective straight line 53 that extends fromthe central hole axis 33 of the fixation hole 32 at the geometric center48 of the hub 28 to the central hole axis 33 of respective aligned onesof the fixation holes 32 of the array 50. The geometric centers of theapertures 52 can lie on the respective central axes 59. Thus, therespective straight line 53 can be said to intersect the central axis 59of the apertures. The apertures 52 can be partially defined byrespective inner sides that can partially define the fixation hole 32 atthe geometric center 48. The apertures 52 can be partially defined byrespective outer sides that can partially define the respective alignedones of the fixation holes 32 of the array 50. The apertures 52 candefine respective ends that each lie on respective straight lines 55that extend from the central hub axis 35 to a location circumferentiallybetween adjacent ones of the fixation holes 32 of the array 50, withrespect to one or both of a top plan view and bottom plan view of thebone plate 20. One of the adjacent ones of the fixation holes 32 can bedefined by the respective aligned one 32 a of the fixation holes 32. Thecentral hole axis 33 of the other 32 b of the adjacent ones of thefixation holes 32 can lie on the respective straight line 55 thatextends to the central hole axis 33 of the fixation hole 32 at thegeometric center 48 of the hub 28 without passing through any of theapertures 52.

As described above, the apertures 52 can be elongate along therespective central axis 59. For instance, the apertures 52 can be dogbone shaped in one example. However, the apertures 52 can define anysuitable alternative shape as desired. For instance, the apertures 52can be oval shaped or rectangular. Alternatively, the apertures 52 canbe constructed as a circle, a regular polygon, or an irregular polygon.Further, the apertures 52 can be circumferentially equidistantly spacedfrom each other. Alternatively, the apertures 52 can be variably spacedfrom each other. Further still, the apertures 52 can be constructed suchthat their respective geometric centers are not in circumferentialalignment with each other.

The apertures 52 can be sized greater than the fixation holes 32. Forinstance, the apertures 52 can be sufficiently sized so as to definevisualization windows that allow for visibility of the underlyingpatella. For instance, the user can visualize the patella through thevisualization windows both as the bone plate 20 is being placed onto thepatella, and after the bone plate 20 has been placed onto the patella.Thus, the surgeon can visually align the fixation holes 32 withrespective bone fragments to which the bone plate 20 is to be secured.The apertures 52 can further assist in the malleability of the boneplate 20, which allows the bone plate 20 to be bent as desired so as tobetter conform to the patella. Further, the apertures 52 can defineherniation holes that allow for soft tissue to herniate through theapertures 52. For instance, when the bone plate 20 is placed against thepatella and secured to the patella, soft tissue residing between thepatella bone and the bone plate 20 can herniate through the apertures52, thereby reducing the profile of the bone plate 20 with respect tothe epidermis.

With continuing reference to FIGS. 3A-3D, and as described above, thefixation body 26 can include a plurality of fixation nodes 54 that aredisposed radially outward with respect to the fixation hub 28. Thefixation nodes 54 can be supported by the fixation hub 28. Each of thefixation nodes 54 can define at least one fixation hole 32. Thus, thefixation nodes 54 can be configured to secure to one or more bonefragments of the patella 23 as desired. For instance, each of thefixation nodes 54 can define a single fixation hole 32. In one example,each of the fixation nodes 54 can define an eyelet 56 that, in turn,defines the fixation hole 32. The eyelet 56 can define an annular wallhaving an inner surface that defines the interior surface 42 of therespective fixation hole 32. The eyelet 56 can further define an outersurface 61 opposite the inner surface that defines an exterior surface43 of the fixation node 54.

The bone plate 20, and in particular the body 26 of the bone plate 20,can define at least one arm 58, such as a plurality of arms 58, thatextends radially outward from the fixation hub 28 to a respective atleast one of the fixation nodes 54. Thus, each of the fixation nodes 54can be attached to the fixation hub 28 by the respective arms 58. Forinstance, the at least one arm 58 can extend to the outer surface 61 ofthe eyelet 56. In one example, the at least one arm 58 can include atleast one pair of arms 58 that includes first and second arms 58 a and58 b. Thus, each of the fixation nodes 54 can be secured to the fixationhub 28 by a respective pair of arms 58. Each pair of arms 58 can bedefined by a first arm 58 a and a second arm 58 b. The arms 58 a and 58b of each pair can converge toward each other as they extend from thefixation hub 28 to the respective one of the fixation nodes 54. Each ofthe arms 58 can be devoid of fixation holes that are designed andconfigured to receive a fixation screw so as to attach the bone plate 20to the underlying bone 21. Further, each of the arms 58 can extend fromthe fixation hub 28 to the respective one of the nodes 54 along an armaxis that intersects the central hole axis 33 of a respective alignedone of the fixation holes 32 of the array 50. The respective aligned oneof the fixation holes 32 of the first arm 58 a can be adjacent to therespective aligned one of the fixation holes 32 of the second arm 58 balong the array 50.

Referring to FIG. 3F, the inner surface 22 at the arms 58 can berecessed toward the outer surface 24 with respect to the inner surface22 at each of the fixation nodes 54 and the fixation hub 28. Thus, aswill be described in more detail below, the inner surface 22 at thefixation hub 28 and the nodes 54 can be configured to abut theunderlying bone 21, while the arms 58 remain spaced from the underlyingbone 21. Further, the inner surface 22 of the bone plate 20 can beplanar. The outer surface 24 of the bone plate 20 can be rounded.Referring again to FIGS. 3A-3B, the first and second arms 58 a and 58 bof each pair of arms 58 can cooperate with the fixation hub 28 so as todefine a respective aperture 60 that extends through the fixation body26. Thus, the apertures 60 can extend through the fixation body 26 at alocation radially between the fixation nodes 54 and the fixation hub 28.The apertures 60 can be referred to as outer apertures. The apertures 52can be referred to as inner apertures.

The apertures 60 can be sized greater than the fixation holes 32. Forinstance, the apertures 60 can be sufficiently sized so as to definevisualization windows that allow for visibility of the underlyingpatella. For instance, the user can visualize the patella through thevisualization windows both as the bone plate 20 is being placed onto thepatella, and after the bone plate 20 has been placed onto the patella.Thus, the surgeon can visually align the fixation holes 32 withrespective bone fragments to which the bone plate 20 is to be secured.The apertures 60 can further assist in the malleability of the boneplate 20, which allows the bone plate 20 to be bent as desired so as tobetter conform to the patella. Further, the apertures 60 can defineherniation holes that allow for soft tissue to herniate through theapertures 60. For instance, when the bone plate 20 is placed against thepatella and secured to the patella, soft tissue residing between thepatella bone and the bone plate 20 can herniate through the apertures60, thereby reducing the profile of the bone plate 20 with respect tothe epidermis.

The fixation nodes 54 of at least one first pair of adjacent fixationnodes 54 can be spaced circumferentially from each other a firstdistance, and the fixation nodes 54 of at least one second pair ofadjacent fixation nodes 54 can be spaced circumferentially from eachother a second distance that is different than the first distance. Forinstance, the second distance can be greater than the first distance.The at least one first pair of adjacent fixation nodes 54 can be definedby all pairs of adjacent fixation nodes 54, with respect to a singlepair that defines the second pair of adjacent fixation nodes 54. Thefixation nodes 54 of the second pair can be the inferior-most fixationnodes 54 of the bone plate 20 when the bone plate 20 is secured to thepatella 23. It should be appreciated that the nodes 54 can be arrangedabout the fixation hub 28 in any manner as desired. For instance, thesecond distance can be equal to the first distance. Thus, in oneexample, the fixation nodes 54 can be equidistantly spacedcircumferentially about the fixation hub 28. While the bone plate 20 caninclude six fixation nodes 54, it should be appreciated that the boneplate 20 can include any number of fixation nodes 54 as desired. Forinstance, the bone plate 20 can include more than six fixation nodes 54.Alternatively, the bone plate 20 can include fewer than six fixationnodes 54.

Referring now to FIGS. 3A-3D, and as described above, the bone plate 20can further include at least one fixation leg 29, such as a plurality offixation legs 29, that extends out from the fixation body 26. Each ofthe fixation legs 29 can include at least one fixation hole 32. Thus,each of the fixation legs 29 can be configured to secure to the patella23 or one or more bone fragments of the patella 23 as desired. Thefixation legs 29 can include a first fixation leg 62 that is configuredto be secured to an inferior medial aspect of the patella 23. Thus, inone example, the first fixation leg 62 can be referred to as an inferiormedial fixation leg. The first fixation leg 62 can extend bothinferiorly and medially from the fixation body 26, and thus can beconfigured to secure to an inferior medial aspect of the patella 23. Thefixation legs 29 can further include a second fixation leg 64 that isconfigured to be secured to an inferior lateral aspect of the patella23. Thus, the second fixation leg 64 can be referred to as an inferiorlateral fixation leg. The second fixation leg 64 can extend bothinferiorly and laterally from the fixation body 26, and thus can beconfigured to secure to a lateral inferior aspect of the patella 23. Thefixation legs 29 can further include a third fixation leg 66 that isconfigured to be secured to the inferior pole of the patella 23. Thus,the third fixation leg 66 can be referred to as an inferior fixation leg66 in certain examples. The third fixation leg 66 can becircumferentially disposed between the first and second fixation legs 62and 64. The hub, the nodes, and the legs 62-66 can all be monolithicwith each other so as to define a single unitary structure. It should beappreciated that the at least one fixation leg 29 can include one ormore up to all of the first, second, and third fixation legs 62-66.Thus, reference to the second leg 64 does not necessarily imply that thebone plate 20 includes the first leg 62. Further, reference to the thirdleg 66 does not necessarily imply that the bone plate 20 includes thefirst and second legs 62 and 64, respectively.

It should be appreciated that the bone plate 20 can be configured to besecured to the patella of a patent's right knee or a patient's leftknee. In this regard, it should be appreciated that the medial fixationleg when the bone plate 20 is secured to the patella of a patient'sright knee becomes the lateral fixation leg when the bone plate 20 issecured to the patella of a patient's left knee. Similarly, the lateralfixation leg when the bone plate 20 is secured to the patella of apatient's right knee becomes the medial fixation leg when the bone plate20 is secured to the patella of a patient's left knee. Thus, referenceto the medial fixation leg 62 and the lateral fixation leg 64 is by wayof example only, it being appreciated that the medial fixation leg 62and the lateral fixation leg 64 can be reversed.

The fixation legs 29 can extend from any location of the fixation body26 as desired. In one example, the first fixation leg 62 can extend froma first one of the fixation nodes 54. The second fixation leg 64 cansimilarly extend from a second one of the fixation nodes 54. The firstand second fixation nodes 54 can define the second pair of fixationnodes 54 described above. The third fixation leg 66 can extend from thefixation body 26 at a location between the first and second ones of thefixation nodes 54 of the second pair. In one example, the third fixationleg 66 can extend from an eyelet that defines one of the fixation holes32 of the array 50. In particular, the third fixation leg 66 can extendfrom the eyelet that defines the inferior-most one of the fixation holes32 of the array 50, and thus of the fixation hub 28. Thus, the thirdfixation leg 66 can be elongate along a respective central axis thatintersects the central hole axis 33 of the inferior-most fixation hole32 of the fixation hub 28. The first and second fixation legs 62 and 64can extend from the fixation body 26 along respective central axes thatare offset from the central hub axis 35. The third fixation leg 66 canextend from the fixation body 26 along a respective central axis thatintersects the central hub axis 35.

The fixation legs 29 can define any number of fixation holes 32 asdesired. In one example, the first fixation leg 62 can define first andsecond fixation holes 32 that are spaced from each other radially alongthe fixation leg 62. In particular, the first fixation leg 62 cansupport at least one medial eyelet 68 that defines a respective fixationhole 32. In one example, the at least one medial eyelet 68 can includefirst and second medial eyelets 68 that each defines a respectivefixation hole 32. The first medial eyelet 68 can be disposed at a distalterminal end of the first fixation leg 62. Thus, the first medial eyelet68 can also be referred to as a terminal medial eyelet 68. The fixationhole 32 defined by the first medial eyelet 68 can be referred to as aterminal fixation hole 32 The second medial eyelet 68 can be disposedbetween the fixation body 26 and the terminal end of the first fixationleg 62. Thus, the second medial eyelet 68 can be referred to as anintermediate medial eyelet 68. The fixation hole 32 defined by thesecond medial eyelet 68 can be referred to as an intermediate medialfixation hole 32. It should be appreciated that the first fixation leg62 can include any number of intermediate medial eyelets 68 as desired.The intermediate medial eyelets 68 can be spaced from each other alongthe respective first fixation leg 62. Alternatively, as illustrated inFIGS. 4A-4B, the at least one medial eyelet 68 can include only thefirst medial eyelet 68 and no other medial eyelets 68.

The second fixation leg 64 can also define first and second fixationholes 32 that are spaced from each other radially along the secondfixation leg 64. In particular, the second fixation leg 64 can supportat least one lateral eyelet 70 that defines a respective fixation hole32. In one example, the at least one lateral eyelet 70 can include firstand second lateral eyelets 70 that each defines a respective fixationhole 32. The first lateral eyelet 70 can be disposed at a distalterminal end of the second fixation leg 64. Thus, the first lateraleyelet 70 can also be referred to as a terminal lateral eyelet 70. Thefixation hole 32 defined by the first lateral eyelet 70 can be referredto as a terminal fixation hole 32 The second lateral eyelet 70 can bedisposed between the fixation body 26 and the terminal end of the secondfixation leg 64. Thus, the second lateral eyelet 70 can be referred toas an intermediate lateral eyelet 70. The fixation hole 32 defined bythe second lateral eyelet 70 can be referred to as an intermediatelateral fixation hole 32. It should be appreciated that the secondfixation leg 64 can include any number of intermediate lateral eyelets70 as desired. The intermediate lateral eyelets can be spaced from eachother radially along the respective second fixation leg 64.Alternatively, as illustrated in FIGS. 4A-4B, the at least one lateraleyelet 70 can include only the first lateral eyelet 70 and no otherlateral eyelets 70.

The third fixation leg 66 can also define first and second fixationholes 32 that are spaced from each other radially along the thirdfixation leg 66. In particular, the third fixation leg 66 can support atleast one inferior eyelet 72 that defines a respective fixation hole 32.In one example, the at least one inferior eyelet 72 can include firstand second inferior eyelets 72 that each defines a respective fixationhole 32. The first inferior eyelet 72 can be disposed at a distalterminal end of the third fixation leg 66. Thus, the first inferioreyelet 72 can also be referred to as a terminal inferior eyelet 72. Thefixation hole 32 defined by the first inferior eyelet 72 can be referredto as a terminal fixation hole 32. The second inferior eyelet 72 can bedisposed between the fixation body 26 and the terminal end of the thirdfixation leg 66. Thus, the second inferior eyelet 72 can be referred toas an intermediate inferior eyelet 72. The fixation hole 32 defined bythe second inferior eyelet 72 can be referred to as an intermediateinferior fixation hole 32. It should be appreciated that the thirdfixation leg 66 can include any number of intermediate inferior eyelets72 as desired. The intermediate inferior eyelets 72 can be spaced fromeach other radially along the respective third fixation leg 66.Alternatively, as illustrated in FIGS. 4A-4B, the at least one inferioreyelet 68 can include only the first inferior eyelet 72 and no otherinferior eyelets 72.

In this regard, referring to FIGS. 4A-4B, it should be appreciated thebone plate 20 can be constructed with shorter fixation legs 29 thanthose illustrated in FIGS. 3A-3E. Otherwise stated, the at least one ofthe first, second and third fixation legs 62-66 of the bone plate 20illustrated in FIGS. 4A-4B can be shorter than a corresponding at leastone of the first, second and third fixation 62-66 the bone plate 20illustrated in FIGS. 3A-3F. Thus, as will be appreciated with respect tothe description of FIGS. 9A-9E below, a surgeon can select the boneplate illustrated in FIGS. 3A-3F if additional positional flexibilityfor the bone anchors is desired along the fixation legs 29.Alternatively or additionally, the surgeon can select the bone plateillustrated in FIGS. 3A-3F if additional length of at least one of thefixation legs 29 is desired. Additional length can be desired to allowthe bone anchor to be driven into one of the bone fragments.Alternatively or additionally, additional length of at least one or moreof the fixation legs 29 may be desired in order to bend the one or morefixation legs 29 in such a manner so as to cradle and compress the bonefragments against each other. The fixation body 26 of the bone plate 20illustrated in FIGS. 4A-4B can be as described with respect to the boneplate illustrated in FIGS. 3A-3F. Thus, the description of the fixationbody 26 with respect to FIGS. 3A-3F can apply equally to the fixationbody 26 illustrated in FIGS. 4A-4B.

Alternatively still, referring to FIGS. 5A-5B, the bone plate 20 can beconstructed without one or more of the fixation legs 29 up to all of thefixation legs 29. Thus, as will be appreciated with respect to thedescription of FIGS. 9A-9E below, a surgeon can select the bone plate 20illustrated in FIGS. 5A-5B if it is not desired to secure the bone plateto the inferior aspect of the patella 23. The fixation body 26 of thebone plate 20 illustrated in FIGS. 5A-5B is the same as the fixationbody 26 illustrated and described above with respect to the bone plate20 illustrated in FIGS. 3A-3F. Thus, the description of the fixationbody 26 with respect to FIGS. 3A-3F can apply equally to the fixationbody 26 illustrated in FIGS. 5A-5B. In one example, the outer surface 24of the bone plate 20 illustrated in FIGS. 5A-5B can define an open areathat is a percentage of an overall area of the outer surface 24. Theoverall area of the outer surface 24 can be measured by determining thearea of the outer surface 24 when the bone plate 20 does not include anyof the fixation holes 32, apertures 52, and apertures 60. Thus, theoverall area of the outer surface 24 can be calculated when an entiretyof the outer surface is continuous and uninterrupted. The actual area ofthe outer surface 24 of the bone plate 20 can be determined includingall disruptions. The disruptions can be defined by the fixation holes32, the apertures 52, and the apertures 60. The actual area can besubtracted from the overall area to determine the open area of the outersurface 24. The open area can be a percentage of the overall area. Forinstance, the percentage can be in a range from 38% to 60%. In oneexample, the percentage can range from 40% to 50%. For instance, thepercentage can be 43%+/−3%. Thus, as described above, the bone plate 20can be malleable, and can include visualization windows and herniationwindows while, at the same time, being sufficiently rigid. The boneplate 20 can be constructed to define any suitable overall area asdesired. In one example, the overall area can be less than 1000 mm². Forinstance, the overall area can be between 200 mm² and 900 mm². In oneexample, the overall area can be between 300 mm² and 900 mm². Forinstance, the overall area can be between 400 mm² and 600 mm².

As illustrated in FIG. 3F, the inner surface 22 of the bone plate 20 atthe first fixation leg 62 can be recessed toward the outer surface 24with respect to the inner surface 22 at each of the at least one medialeyelet 68. Thus, as will be described in more detail below, the innersurface 22 at the at least one medial eyelet 68 can be configured toabut the underlying bone 21, while the inner surface 22 at the firstfixation leg 62 remain spaced from the underlying bone 21. Further, theinner surface 22 of the bone plate 20 at the second fixation leg 64 canbe recessed toward the outer surface 24 with respect to the innersurface 22 at each at least one lateral eyelet 70. Thus, as will bedescribed in more detail below, the inner surface 22 at the at least onelateral eyelet 70 can be configured to abut the underlying bone 21,while the inner surface 22 at the second fixation leg 64 remains spacedfrom the underlying bone 21. Further, the inner surface 22 of the boneplate 20 at the third fixation leg 66 can be recessed toward the outersurface 24 with respect to the inner surface 22 at each at least oneinferior eyelet 72. Thus, as will be described in more detail below, theinner surface 22 at the at least one inferior eyelet 72 can beconfigured to abut the underlying bone 21, while the inner surface 22 atthe third fixation leg 66 remains spaced from the underlying bone 21.

The fixation legs 29 can extend tangential to the curvature of the domeshape of the fixation body 26 as illustrated in FIG. 3E. Further, thefirst, second, and third fixation legs 62, 64, and 66, respectively, canbe circumferentially spaced from each other, thus, the first, second,and third fixation legs 62, 64, and 66 can all lie on respectivedifferent planes.

Referring now to FIGS. 6A-6B, the bone plate 20 can be configured asdescribed above with respect to FIGS. 3A-3F. However, in FIGS. 6A-6B,the fixation hub 28 can include first and second arrays 50 and 51 offixation holes 32. In this regard, the array 50 of fixation holes 32described above with respect to the bone plate 20 illustrated in FIGS.3A-3F can be referred to as a first array 50 of fixation holes. Asillustrated in FIGS. 6A-6B, the fixation hub 28 can include the secondarray 51 of fixation holes 32. Thus, the fixation hub 28 of the boneplate 20 illustrated in FIGS. 6A-6B can be sized larger than thefixation hub 28 of the bone plate 20 illustrated in FIGS. 3A-5B so as toinclude the first and second arrays 50 and 51 of fixation holes 32.Further, because the bone plate 20 illustrated in FIGS. 6A-6B includesthe additional second array 51 of fixation holes 32, the bone plate 20illustrated in FIGS. 6A-6B can allow for fixation to bone fragments atadditional locations with respect to the bone plate 20 illustrated inFIGS. 3A-5B having only the single array 50 of fixation holes 32.

The second array 51 can be configured as a circumferential array. Thus,the second array can surround the geometric center 48 of the hub 28. Thefixation holes 32 of the second array 51 can be offset radially outwardwith respect to the fixation holes 32 of the first array 50. Forinstance, the respective hole axes of the fixation holes 32 of the firstarray 50 can be spaced from the central hub axis 35 a first distance,and the respective hole axes of the fixation holes 32 of the secondarray 51 can be spaced from the central hub axis 35 a second distancethat is greater than the first distance. Thus, the first array 50 offixation holes 32 can be referred to as an inner array, and the secondarray 51 of fixation holes 32 can be referred to as an outer array. Thefirst array 50 of fixation holes can be constructed as described abovewith respect to the bone plate illustrated in FIGS. 3A-5B.

The fixation holes 32 of the second array 51 can be arranged along apath that extends about the geometric center 48. For instance, the pathof the second array can be a closed path that surrounds the geometriccenter 48. In one example, the path of the second array 51 can define asecond circle. The central hub axis 35 can define the center of thesecond circle. Thus, the second circle can be concentric with the circledefined by the central hole axes 33 of the fixation holes 32 of thefirst array 50. The circle defined by the central hole axes 33 of thefixation holes 32 of the first array 50 can be referred to as a firstcircle. The first circle can be can be disposed between the secondcircle and the central hub axis 35. The central hole axes 33 (see FIG.2B) of the fixation holes 32 of the second array 51 can lie on thesecond circle.

In one example, the fixation holes 32 of the second array 51 can bespaced equidistantly from each other along the second circle.Alternatively, the fixation holes 32 can be spaced at variable distancesfrom each other. Further, while the fixation holes 32 of the secondarray 51 can be arranged on the circular path, it should be appreciatedthat the fixation holes 32 of the second array 51 can be alternativelyarranged as desired. For instance, the fixation holes 32 of the secondarray 51 can lie on any curved path. The curved path can define anellipse in one example. Alternatively, the path can define a polygon.For instance, the central hole axes 33 of the fixation holes of thesecond array 51 can define the vertices, respectively, of the polygon.In one example, as illustrated in FIGS. 5A-5B, the polygon can be aregular polygon. Alternatively, the polygon can be an irregular polygon.

In one example, the second array 51 can include six fixation holes 32.Thus, the regular polygon can be configured as a hexagon. It should beappreciated, however, that the second array 51 can include any number offixation holes 32 as desired. In one example, the fixation hole 32 atthe geometric center 48 and the fixation holes 32 of the first andsecond arrays 50 and 51 can constitute all fixation holes 32 of thefixation hub 28. Alternatively, the fixation hub 28 can include at leastone additional fixation hole 32 in addition to the fixation hole 32 atthe geometric center 48 and the fixation holes 32 of the first andsecond arrays 50 and 51. The at least one additional fixation hole 32can be disposed between the geometric center 48 and the array 50.Alternatively or additionally, the at least one additional fixation hole32 can be disposed between the first array 50 and the second array 51.Alternatively or additionally still, the at least one additionalfixation hole 32 can be disposed radially outward of the second array51. Thus, the second array 51 can be disposed between the at least oneadditional fixation hole 32 and the geometric center 48.

The radially outer surfaces of the eyelets that define the fixationholes 32 of the first and second arrays 50 and 51 can define the outerperimeter of the fixation body 26. The radially outer surfaces of theeyelets that define the fixation holes 32 of the second array 51 can beoffset radially outward (i.e., away from the central hub axis 35) withrespect the radially outer surfaces of the eyelets that define thefixation holes 32 of the first array 50. Further, eyelets that definethe fixation holes 32 of the first array 50 can be alternatinglyarranged with the eyelets that define the fixation holes 32 of thesecond array 51. Thus, each of the eyelets that define the fixationholes 32 of the first array 50 can be interconnected between adjacentones of the eyelets that define the fixation holes 32 of the secondarray 51. Further, each of the eyelets that define the fixation holes 32of the second array 51 can be interconnected between adjacent ones ofthe eyelets that define the fixation holes 32 of the first array 50.

The apertures 52 can be positioned circumferentially offset with respectto the fixation holes 32 of the first array 50. For instance, thestraight lines 53 that intersect each of the central hub axis 35 and thecentral hole axes of respective ones of the fixation holes 32 of thefirst array 50 do not intersect the apertures 52 with respect to a topor bottom plan view of the bone plate 20. That is, the straight lines 53can be circumferentially offset from the apertures 52. For instance, thestraight lines 53 can be circumferentially equidistantly spaced fromadjacent ones of the apertures 52.

Further, the apertures 52 can be elongate along the radial direction.Thus, in one example, the central axes 59 of the apertures 52 canintersect the central hub axis 35. Further, the central axes 59 of theapertures 52 can intersect the central hole axis of a respective alignedone of the fixation holes 32 of the second array 51. Thus, the apertures52 can be disposed radially between a respective one of the fixationholes 32 of the second array and the geometric center of the hub 28.Further, the apertures 52 can be disposed between adjacent ones of thefixation holes 32 of the first array 50 with respect to thecircumferential direction. Accordingly, straight lines 76 can passthrough the central hub axis 35, the central hole axis 33 of arespective one of the fixation holes 32 of the second array 51, and canbe coincident with the central axis 59 of a respective one of theapertures 52 with respect to a top or bottom plan view of the boneplate. The apertures 52 can be define any suitable shape as desired. Inone example, the apertures 52 can define the shape of an arrow thatpoints toward the geometric center 48. Further, the apertures 52 canspan a majority of the radial distance from a respective aligned one ofthe fixation holes 32 of the second array 51 and the fixation hole 32 atthe geometric center 48.

The geometric centers of the apertures 52 can lie on a respective circlethat surrounds the geometric center 48 of the hub 28. For instance, thegeometric center 48 of the hub 28 can define the center of the circledefined by the geometric centers of the apertures 52. Thus, the circledefined by the geometric centers of the apertures 52 can be concentricwith each of the first and second circles. Further, in one example, thefirst circle can be disposed between the circle defined by the geometriccenters of the apertures 52 and the second circle.

With continuing reference to FIGS. 6A-6B, and as described above, thefixation body 26 can include the plurality of fixation nodes 54 that areconnected to the hub 28. In particular, the fixation body 26 includes atleast one arm 58, such as a plurality of arms 58, that extends radiallyoutward from the fixation hub 28 to a respective at least one of thefixation nodes 54. Thus, each of the fixation nodes 54 can be attachedto the fixation hub 28 by the respective arms 58. For instance, the atleast one arm 58 can extend to the outer surface 61 of the eyelet 56. Inone example, the at least one arm 58 can include at least one pair ofarms 58 that includes first and second arms 58 a and 58 b. Thus, each ofthe fixation nodes 54 can be secured to the fixation hub 28 by arespective pair of arms 58. Each pair of arms 58 can be defined by afirst arm 58 a and a second arm 58 b. The arms 58 a and 58 b of eachpair can converge toward each other as they extend from the fixation hub28 to the respective one of the fixation nodes 54. Further, each of thearms 58 can extend from the fixation hub 28 to the respective one of thenodes 54 along a arm axis that intersects the central hole axis 33 of arespective aligned one of the fixation holes 32 of the second array 51.The respective aligned one of the fixation holes 32 of the first arm 58a can be adjacent to the respective aligned one of the fixation holes 32of the second arm 58 b along the array 50.

Further, the first and second arms 58 a and 58 b of each pair of arms 58can cooperate with the fixation hub 28 so as to define a respectiveaperture 60 that extends through the fixation body 26. Thus, theapertures 60 can extend through the fixation body 26 at a locationradially between the fixation nodes 54 and the fixation hub 28. Theapertures 60 can be referred to as outer apertures. The apertures 52 canbe referred to as inner apertures. The outer apertures 60 can be definedby a respective one of the nodes 54, a respective pair of adjacenteyelets that defines respective fixation holes 32 of the second array51, and a respective one of the eyelets that defines the fixation hole32 of the first array 50. The respective one of the eyelets that definesthe fixation hole 32 of the first array 50 is interconnected between theadjacent eyelets of the respective pair of eyelets that defines therespective fixation holes 32 of the second array.

Further still, the bone plate illustrated in FIGS. 6A-6B can include atleast fixation leg 29 in the manner described above with respect toFIGS. 3A-3F. Thus, the description of the legs 62-66 above with respectto FIGS. 3A-3F can apply to the fixation legs 62-66 illustrated in FIGS.6A-6B unless otherwise indicated. The at least one fixation leg 29 caninclude the first fixation leg 62 that is configured to be secured to amedial aspect of the patella 23, the second fixation leg 64 that isconfigured to be secured to a lateral aspect of the patella 23, and thethird fixation leg 66 that is configured to be secured to the inferiorpole of the patella 23. The fixation legs 29 can extend from anylocation of the fixation body 26 as desired. In one example, the firstfixation leg 62 can extend from a first one of the fixation nodes 54.The second fixation leg 64 can similarly extend from a second one of thefixation nodes 54. The third fixation leg 66 can extend from thefixation body 26 at a location between the first and second ones of thefixation nodes 54. In one example, the third fixation leg 66 can extendfrom an eyelet that defines one of the fixation holes 32 of the secondarray 51. In particular, the third fixation leg 66 can extend from theeyelet that defines the inferior-most one of the fixation holes 32 ofthe second array 51, and thus of the fixation hub 28. Thus, the thirdfixation leg 66 can be elongate along a respective central axis thatintersects the central hole axis of the inferior-most fixation hole 32of the fixation hub 28. The inferior-most one of the fixation holes 32of the second array 51 can be interconnected between the first andsecond ones of the fixation nodes 54.

Referring now to FIGS. 6A-8B generally, the fixation legs 29 can defineany number of fixation holes 32 as desired. In one example illustratedin FIGS. 6A-6B, the first fixation leg 62 can define first and secondfixation holes 32 that are spaced from each other radially along thefixation leg 62. In particular, the first fixation leg 62 can support atleast one medial eyelet 68 that defines a respective fixation hole 32.In one example, the at least one medial eyelet 68 can include first andsecond medial eyelets 68 that each defines a respective fixation hole32. The first medial eyelet 68 can be disposed at a distal terminal endof the first fixation leg 62. Thus, the first medial eyelet 68 can alsobe referred to as a terminal medial eyelet 68. The fixation hole 32defined by the first medial eyelet 68 can be referred to as a terminalfixation hole 32 The second medial eyelet 68 can be disposed between thefixation body 26 and the terminal end of the first fixation leg 62.Thus, the second medial eyelet 68 can be referred to as an intermediatemedial eyelet 68. The fixation hole 32 defined by the second medialeyelet 68 can be referred to as an intermediate medial fixation hole 32.It should be appreciated that the first fixation leg 62 can include anynumber of intermediate medial eyelets 68 as desired. The intermediatemedial eyelets 68 can be spaced from each other along the respectivefirst fixation leg 62. Alternatively, as illustrated in FIGS. 7A-7B, theat least one medial eyelet 68 can include only the first medial eyelet68 and no other medial eyelets 68.

The second fixation leg 64 can also define first and second fixationholes 32 that are spaced from each other radially along the secondfixation leg 64. In particular, the second fixation leg 64 can supportat least one lateral eyelet 70 that defines a respective fixation hole32. In one example, the at least one lateral eyelet 70 can include firstand second lateral eyelets 70 that each defines a respective fixationhole 32. The first lateral eyelet 70 can be disposed at a distalterminal end of the second fixation leg 64. Thus, the first lateraleyelet 70 can also be referred to as a terminal lateral eyelet 70. Thefixation hole 32 defined by the first lateral eyelet 70 can be referredto as a terminal fixation hole 32 The second lateral eyelet 70 can bedisposed between the fixation body 26 and the terminal end of the secondfixation leg 64. Thus, the second lateral eyelet 70 can be referred toas an intermediate lateral eyelet 70. The fixation hole 32 defined bythe second lateral eyelet 70 can be referred to as an intermediatelateral fixation hole 32. It should be appreciated that the secondfixation leg 64 can include any number of intermediate lateral eyelets70 as desired. The intermediate lateral eyelets can be spaced from eachother radially along the respective second fixation leg 64.Alternatively, as illustrated in FIGS. 7A-7B, the at least one lateraleyelet 70 can include only the first lateral eyelet 70 and no otherlateral eyelets 70.

The third fixation leg 66 can also define first and second fixationholes 32 that are spaced from each other radially along the thirdfixation leg 66. In particular, the third fixation leg 66 can support atleast one inferior eyelet 72 that defines a respective fixation hole 32.In one example, the at least one inferior eyelet 72 can include firstand second inferior eyelets 72 that each defines a respective fixationhole 32. The first inferior eyelet 72 can be disposed at a distalterminal end of the third fixation leg 66. Thus, the first inferioreyelet 72 can also be referred to as a terminal inferior eyelet 72. Thefixation hole 32 defined by the first inferior eyelet 72 can be referredto as a terminal fixation hole 32. The second inferior eyelet 72 can bedisposed between the fixation body 26 and the terminal end of the thirdfixation leg 66. Thus, the second inferior eyelet 72 can be referred toas an intermediate inferior eyelet 72. The fixation hole 32 defined bythe second inferior eyelet 72 can be referred to as an intermediateinferior fixation hole 32. It should be appreciated that the thirdfixation leg 66 can include any number of intermediate inferior eyelets72 as desired. The intermediate inferior eyelets 72 can be spaced fromeach other radially along the respective third fixation leg 66.Alternatively, as illustrated in FIGS. 7A-7B, the at least one inferioreyelet 68 can include only the first inferior eyelet 72 and no otherinferior eyelets 72.

In this regard, referring to FIGS. 7A-7B, it should be appreciated thebone plate 20 can be constructed with shorter fixation legs 29 thanthose illustrated in FIGS. 6A-6B. Otherwise stated, the at least one ofthe first, second and third fixation legs 62-66 of the bone plate 20illustrated in FIGS. 7A-7B can be shorter than a corresponding at leastone of the first, second and third fixation 62-66 the bone plate 20illustrated in FIGS. 6A-6F. The fixation body 26 of the bone plate 20illustrated in FIGS. 7A-7B can be as described with respect to the boneplate illustrated in FIGS. 6A-6B. Thus, the description of the fixationbody 26 with respect to FIGS. 6A-6B can apply equally to the fixationbody 26 illustrated in FIGS. 7A-7B.

Alternatively still, referring to FIGS. 8A-8B, the bone plate 20 can beconstructed without one or more of the fixation legs 29 up to all of thefixation legs 29. Thus, the bone plate 20 can include the fixation body26 including the fixation hub 28 and the fixation nodes 54, but nofixation legs 29. The fixation body 26 of the bone plate 20 illustratedin FIGS. 8A-8B is the same as the fixation body 26 illustrated anddescribed above with respect to the bone plate 20 illustrated in FIGS.6A-6B. Thus, the description of the fixation body 26 with respect toFIGS. 6A-6B can apply equally to the fixation body 26 illustrated inFIGS. 8A-8B. In one example, the outer surface 24 of the bone plate 20illustrated in FIGS. 8A-8B can define an open area that is a percentageof an overall area of the outer surface 24. The overall area of theouter surface 24 can be measured by determining the area of the outersurface 24 when the bone plate 20 does not include any of the fixationholes 32, apertures 52, and apertures 60. Thus, the overall area of theouter surface 24 can be calculated when an entirety of the outer surfaceis continuous and uninterrupted. The actual area of the outer surface 24of the bone plate 20 can be determined including all disruptions. Thedisruptions can be defined by the fixation holes 32, the apertures 52,and the apertures 60. The actual area can be subtracted from the overallarea to determine the open area of the outer surface 24. The open areacan be a percentage of the overall area. For instance, the percentagegreater than 27%. For instance, the percentage can range from 27% to65%. In one example, the percentage can range from 30% to 60%. Forinstance, the percentage can range from 40% to 60%. In one example, thepercentage can be substantially 55%. Thus, as described above, the boneplate 20 can be malleable, and can include visualization windows andherniation windows while, at the same time, being sufficiently rigid.The bone plate 20 can be constructed to define any suitable overall areaas desired. In one example, the overall area can be greater than 900mm². For instance, the overall area can be greater than 1000 mm². In oneexample, the overall area can range from 900 mm² and 1500 mm². Forinstance, the overall area can range from 900 mm² to 1200 mm². Forinstance, the overall area can range from 900 mm² to 1100 mm².

Thus, referring to FIGS. 3A-8B in general, it can be said that thefixation body 26, and thus the bone plate 20, includes at least onearray of fixation holes 32 that extend through the hub 28. The at leastone array can include a single array 50 as illustrated in FIGS. 3A-5B.Alternatively, the at least one array can include first and secondarrays 50 and 51 as illustrated in FIGS. 6A-8B. It should beappreciated, however, that the fixation body 26 can include any suitablenumber of arrays of fixation holes 32 that extend through the fixationhub 28 as desired. Further, it can be said that the bone plate 20 caninclude at least one fixation leg that extends from the fixation body26. The at least one fixation leg can have a sufficient length to bebent around a peripheral rim of the patella as described in more detailbelow. For instance, the at least one fixation leg can include the firstfixation leg 62, the second fixation leg 64, and the third fixation leg66. The fixation legs 62-66 can define any number of fixation holes 32as desired. For instance, in one example, the fixation legs 62-66 candefine first and second fixation hole 32. In another example, thefixation legs 62-66 can define a single fixation hole 32.

In this regard, it should be appreciated that a kit of bone plates 20can be provided. The kit can include at least one first bone plate 20having a fixation body 26 with the single array 50 of fixation holes 32.The kit can include at least one second bone plate 20 having a fixationbody with the first and second arrays 50 and 51 of fixation holes 32.The second bone plate can be sized larger than the first bone plate. Theat least one first bone plate 20 can include bone plates 20 having theat least one fixation leg 29. Ones of the first bone plates 20 havingthe at least one fixation leg 29 can include different numbers offixation holes 32 that extends through the at least one fixation leg.Alternatively or additionally, the at least one first bone plate 20 caninclude at least one bone plate 20 having no fixation legs 29.Similarly, the at least one second bone plate 20 can include bone plates20 having the at least one fixation leg 29. Ones of the second boneplates 20 having the at least one fixation leg 29 can include differentnumbers of fixation holes 32 that extends through the at least onefixation leg. Alternatively or additionally, the at least one secondbone plate 20 can include at least one bone plate 20 having no fixationlegs 29.

A method of securing the fixation plate 20 to the underlying bone 21will now be described with reference to FIGS. 9A-9D. In particular, themethod can begin by creating an incision that exposes the anterioraspect of the patella 23. Thus, the bone plate 23 can be placed againstthe patella 23 along an anterior approach. As illustrated, the patella23 is fractured and defines a plurality of patellar bone fragments 74.In instances where the patella 23 is severely comminuted, the bonefragments 74 can be compressed against each other thereby reducing thefracture using any suitable clamp or forceps. The bone plate 20 can thenbe placed against the underlying patella 23. The bone plate 20 canfurther be contoured so as to conform to the underlying patella 23. Forinstance, the bone plate body 26 can be contoured by bending one or moreof the arms 58. One or more up to all of the legs 62-66 can also be bentso as to conform to the underlying patella 23. As described above, theinner surface 22 at the arms 58 can be recessed toward the outer surface24 with respect to the inner surface 22 at each of the fixation nodes 54and the fixation hub 28. Further, the inner surface at the legs 29 canbe recessed toward the outer surface 24 with respect to the innersurface 22 at the eyelets that define the fixation holes 32 of the legs29. Thus, the inner surface 22 at the arms 58 and the legs 29 can bespaced from the patella 23. The fixation hub 28, the fixation nodes 54,and the eyelets of the legs 29 (if present) can abut the patella 23.

In this regard, it should be appreciated that the apertures 52 of thebone plate 20 can assist in the malleability of the bone plate 20. Thus,the bone plate 20 can be bent as desired so as to conform to theunderlying patella 23. The apertures 60 of the bone plate 20 of FIGS.6A-8B can further assist in the malleability of the bone plate 20. Thus,the bone plate 20 can be bent in situ to conform to the outer surface ofthe patella 23. In particular, the fixation hub 28 can be bent asdesired to better conform to the outer surface of the patella 23 thanthe preformed dome shape of the fixation hub 28. Further, the arms 58can be bent out of plane. Out of plane bending can include a firstinward direction toward the underlying bone. The inward direction can begenerally defined as from the outer surface 24 to the inner surface 22.Out of plane bending can include a second outward direction away fromthe underlying bone. The outward direction can be generally defined asfrom the inner surface 22 to the inner outer surface 24. Alternativelyor additionally, the arms 58 can be bent in-plane. That is, the arms 58can be bent so as to not move further from or closer to the underlyingpatella while, at the same time, maintaining their respective angularorientations. Alternatively or additionally still, the arms 58 canfurther be twisted so as to adjust the angular orientation of the innersurface 22 at the eyelets that define the fixation holes 32 of the nodes54. Thus, one or more of the arms 58 can be deformed so as to cause theinner surface 22 at the nodes 54 to better conform to the surface of thepatella 23.

In one example, the arms 58 can be bent such that the fixation holes 32of at least one of the nodes 54 can be aligned with the patellar rim.For instance, depending on the size of the bone plate 20 and the size ofthe patella 23, all of the nodes can extend at least to the patellarrim. Thus, the respective bone anchors 34 can be driven through thefixation holes 32 of at least one or more of the nodes 54 and into thepatellar rim in a substantially posterior direction. In another example,at least one or more of the arms 58 can be bent such that the node 54extends about the patellar rim. Thus, the respective bone anchor 34 canbe driven through the fixation hole 32 of the node 54 substantially in aplane that is oriented substantially perpendicular to the posteriordirection.

Further, one or more up to all of the legs 62-66 can be bent as desiredto better conform to the outer surface of the patella 23. For instance,one or more up to all of the legs 62-66 can be bent out of plane.Alternatively or additionally, one or more up to all of the legs 62-66can be bent out in plane. Alternatively or additionally still, one ormore up to all of the legs 62-66 can be twisted so as to adjust theangular orientation of the inner surface 22 at the eyelets that definethe fixation holes 32 of the nodes 54. Thus, one or more of the legs62-66 can be deformed so as to cause the inner surface 22 at the one ormore of the legs 62-66 to better conform to the surface of the patella23.

Once the bone plate 20 has been placed against the patella 23 and bentas desired, the method can including the steps of driving bone anchors34 into respective ones of the fixation holes 32 of the bone plate 20.For instance, the method can include the step of identifying fixationholes 32 of the bone plate 20 that are aligned with one or more bonefragments 74, such that driving a bone anchor 34 through the alignedfixation holes 32 will gain reliable purchase with the bone fragment 74.Next, the bone anchors 34 can be driven into the identified fixationholes 32. In this regard, it is appreciated that the fixation hub 28 caninclude one or more of the identified fixation holes 32. Alternativelyor additionally, the fixation nodes 54 can include one or more of theidentified fixation holes 32.

As illustrated in FIGS. 9A-9B, one of the bone anchors 34 can extendthrough the third fixation leg 66, through a near cortex to a far cortexopposite the near cortex. Thus, the bone anchor 34 can threadedlypurchase with both the near cortex and the far cortex. In one example,the near cortex can be defined by the inferior pole of the patella 23,and the far cortex can be defined by the superior pole of the patella23. As will be appreciated from the description below, it will beappreciated that the near cortex can alternatively be defined by thesuperior pole of the patella 23 and the far cortex can be defined by theinferior pole of the patella. Alternatively, the near cortex can bedefined by the medial cortex of the patella 23 and the far cortex can bedefined by the lateral cortex of the patella. Alternatively still, thenear cortex can be defined by the lateral cortex of the patella 23 andthe far cortex can be defined by the medial cortex of the patella.

It is further recognized that the inferior pole 80 of the patella 23 canoften be comminuted, and can contain osteoporotic bone. In fact,inferior pole comminution has been observed in 88% of fractures of thepatella 23. Accordingly, fixation of the bone plate 20 to the patella 23can be augmented by suture fixation if desired. The method of fixationcan further include the step of augmenting fixation of the bone plate 20to the patella 23 by fixing at least one suture to the patellar tendon82 and to the plate 20. In one example, the sutures can be configured asFiberWire® sutures commercially available from Arthrex, having a placeof business in Naples, Fla., though it should be appreciated that anysuitable suture is envisioned. Thus, the method can include the step ofattaching one or more sutures to the patellar tendon 82. The sutures canthus be included in the fixation system. In one example, the sutures canbe stitched through the patellar tendon 82 in a Krackow configuration.The free end of the suture can then be passed over the plate in theinferior direction, and tied to the plate 20. For instance, the suturescan be inserted through respective ones of the apertures 52 and theapertures 60 (if present) so as to tie the bone plate 20 to the patellartendon 82.

In some examples, as illustrated in FIGS. 9A-9C, the bone plate 20 caninclude at least one leg 29 that extends from the fixation body 26. Theat least one leg 29 (if present) can be deformed so as to cause theinner surface 22 at the at least one eyelet supported by the leg tobetter conform to the surface of the patella 23. For instance, the atleast one leg 29 can be bent in plane, bent out of plane, and twisted asdesired. Thus, the first or inferior medial leg 62 (if present) can bedeformed so as to cause the inner surface 22 at the at least one medialeyelet 68 to abut the patella 23. In one example, the first leg 62 canhave a length sufficient so as to extend around the medial inferior rim78 of the patella 23. Thus, the first leg 62 can be deformed so as tocause the inner surface 22 at the at least one medial eyelet 68 to abutthe patella 23. In one example, the first leg 62 can have a lengthsufficient so as to extend around the medial inferior rim 78 of thepatella 23. The first leg 62 can be deformed such that the respective atleast one fixation hole 32 can receive a bone anchor 34 that reliablysecures the medial leg 62 to a bone fragment 74.

Further, the second or lateral leg 64 (if present) can be deformed so asto cause the inner surface 22 at the at least one lateral eyelet 70 toabut the patella 23. In one example, the second leg 64 can have a lengthsufficient so as to extend around the lateral inferior rim 84 of thepatella 23. Thus, the second leg 64 can be deformed so as to cause theinner surface 22 at the at least one lateral eyelet 70 to abut thepatella 23. In one example, the second leg 64 can have a lengthsufficient so as to extend around the lateral inferior rim 84 of thepatella 23. The second leg 64 can be deformed such that the respectiveat least one fixation hole 32 can receive a bone anchor 34 that reliablysecures the second leg 64 to a bone fragment 74.

Further, still, the third or inferior leg 66 (if present) can bedeformed so as to cause the inner surface 22 at the at least oneinferior eyelet 70 to abut the patella 23. In one example, the third leg66 can have a length sufficient so as to extend around the inferior pole80 of the patella 23. Thus, the third leg 66 can be deformed so as tocause the inner surface 22 at the at least one inferior eyelet 72 toabut the patella inferior pole 80. In one example, the third leg 66 canhave a length sufficient so as to extend around the inferior pole 80.Further, an incision 86 can be made through the patellar tendon 82, andthe third leg 66 can be inserted through the incision 86 so as to restagainst the patella 23 at a position posterior of the patellar tendon82. The third leg 66 can be deformed such that the respective at leastone fixation hole 32 can receive a bone anchor 34 that reliably securesthe third leg 66 to a bone fragment 74. It is further recognized thatthe first leg 62, the second leg 64, and the third leg 66 can all abutthe inferior aspect of the patella 23 in different planes, therebyforming a cradle that maintains comminuted bone fragments compressedagainst adjacent bone fragments. Thus, the first leg 62, the second leg64, and the third leg 66 can apply a compression force to the inferioraspect of the patella 23 that causes the bone fragments 74 to compressagainst each other, thereby facilitating healing.

Referring now to FIG. 9E, it is recognized that some patella fracturesdo not involve comminutions at the inferior pole 80. Accordingly, inorder to avoid creating unnecessary incisions in the patellar tendon 82,the bone plate 20 described above can include the first leg 62 and thesecond leg 64, but can lack the third leg 66. Alternatively, the thirdleg 66 can be removable from the fixation body 26. For instance, acutting implement can sever the third leg 66 from the fixation body 26.Alternatively or additionally, the third leg 66 can define a weakenedbreak-away region. The weakened break-away region can define a materialthickness less than the material thickness at a remainder of theinferior leg. The break-away region can be immediately adjacent thefixation body 26 so as to eliminate potential irritating projections andsharp edges when the third leg 66 is removed. In this regard, any one ormore up to all of the first, second, and third legs 62-66 can be removedfrom the bone plate 20 as desired.

As described above, the bone plate 20 can be oriented such that the atleast one fixation leg 29 extend inferiorly from the fixation body 26.It should be appreciated, of course, that the bone plate 20 can be fixedto the patella 23 in any orientation as desired. For instance, referringto FIG. 10A, the bone plate 20 can be fixed to the patella 23 such thatthe at least one fixation leg 29 extends superiorly from the fixationbody 26. Thus, the first fixation leg 62 can extend to a superior medialaspect of the patella 23. The second fixation leg 64 can extend to asuperior inferior lateral aspect of the patella 23. The third fixationleg 66 can extend to the superior pole of the patella 23. Alternatively,referring to FIG. 10B, the bone plate 20 can be fixed to the patella 23such that the at least one fixation leg 29 extends medially from thefixation body 26. Accordingly, the at least one fixation leg 29 canextend to the medial rim of the patella 23. For instance, the firstfixation leg 62 can extend to an inferior aspect of the medial rim. Thesecond fixation leg 64 can extend to a superior aspect of the medialrim. The third fixation leg 66 can extend to a central region of themedial rim. Alternatively still, referring to FIG. 10C, the bone plate20 can be fixed to the patella 23 such that the at least one fixationleg 29 extends laterally from the fixation body 26. Accordingly, the atleast one fixation leg 29 can extend to the lateral rim of the patella23. For instance, the first fixation leg 62 can extend to a superioraspect of the lateral rim. The second fixation leg 64 can extend to aninferior aspect of the lateral rim. The third fixation leg 66 can extendto a central region of the lateral rim.

As described above, the bone plate 20 can include a group of at leastone fixation leg 29. However, as illustrated in FIG. 11, the bone plate20 can include first and second groups 88 a and 88 b of at least onefixation leg. The first and second groups 88 a and 88 b can bepositioned substantially opposite each other. Thus, the at least one leg29 of one of the first and second groups 88 a and 88 b can extendinferiorly from the fixation body 26 in the manner described above, andthe at least one leg 29 of one of the other of the first and secondgroups 88 a and 88 b can extend superiorly from the fixation body 26 inthe manner described above. Alternatively, the at least one leg 29 ofone of the first and second groups 88 a and 88 b can extend mediallyfrom the fixation body 26 in the manner described above, and the atleast one leg 29 of the other of the first and second groups 88 a and 88b can extend laterally from the fixation body 26 in the manner describedabove.

As illustrated in FIG. 11, the first and second groups 88 a and 88 b canbe spaced at substantially 180 degrees from each other, such that thefirst and second groups 88 a and 88 b are opposite each other. It shouldbe appreciated, of course, that the first and second groups 88 a and 88b can be spaced from each other at any angle as desired. For instance,the first and second groups 88 a and 88 b can be spaced at substantially90 degrees circumferentially from each other. Thus, the at least one leg29 of one of the first and second groups 88 a and 88 b can extendinferiorly from the fixation body 26 in the manner described above, andthe at least one leg 29 of the other of the first and second groups 88 aand 88 b can extend medially or laterally from the fixation body 26 inthe manner described above. Alternatively, the at least one leg 29 ofone of the first and second groups 88 a and 88 b can extend superiorlyfrom the fixation body 26 in the manner described above, and the atleast one leg 29 of the other of the first and second groups 88 a and 88b can extend medially or laterally from the fixation body 26 in themanner described above. Alternatively still, the bone plate 20 caninclude three or more groups of at least one fixation leg 29. Forinstance, the bone plate 20 can include three groups of at least onefixation leg equidistantly spaced about the fixation body 26.Alternatively, the three groups can be spaced at different distancesfrom each other. For instance, adjacent parts of the three groups can bespaced at substantially 90 degrees from each other, and one adjacentpair of the three groups can be spaced at substantially 180 degrees fromeach other. In another example, the bone plate can include four groupsof at least one fixation leg 29 that are spaced equidistantly from eachother. Thus, the at least one fixation leg 29 of a first group of thefour groups can extend inferiorly from the fixation body 26 in themanner descried above, the at least one fixation leg of a second groupof the four groups can extend superiorly from the fixation body 26 inthe manner descried above, the at least one fixation leg of a thirdgroup of the four groups can extend medially from the fixation body 26in the manner descried above, and the at least one fixation leg of afourth group of the four groups can extend laterally from the fixationbody 26 in the manner descried above.

It should be noted that the illustrations and discussions of theembodiments shown in the figures are for exemplary purposes only, andshould not be construed limiting the disclosure. One skilled in the artwill appreciate that the present disclosure contemplates variousembodiments. Additionally, it should be understood that the conceptsdescribed above with the above-described embodiments may be employedalone or in combination with any of the other embodiments describedabove. It should further be appreciated that the various alternativeembodiments described above with respect to one illustrated embodimentcan apply to all embodiments as described herein, unless otherwiseindicated.

What is claimed:
 1. A patella bone plate comprising: a fixation bodyincluding: a fixation hub having an inner surface configured to face apatella bone and an outer surface opposite the inner surface, and anarray of fixation holes that extend through the fixation hub from theinner surface to the outer surface; and a plurality of fixation nodesthat extend from the fixation hub, each of the plurality of fixationnodes defining a respective fixation hole; and at least one leg thatextends out from the body, the at least one leg being deformable andhaving a length sufficient so as to wrap around an inferior rim of thepatella bone, the at least one leg including at least one fixation hole,wherein the at least one leg comprises a medial leg and a lateral legthat extend out from respective eyelets that define adjacent ones of thefixation nodes of the fixation body, and wherein the at least one legcomprises an inferior leg that extends out from the fixation hub at alocation between the respective eyelets.
 2. The patella bone plate asrecited in claim 1, wherein the fixation body has a preformed concavity.3. The patella bone plate as recited in claim 1, wherein the fixationholes of the array are arranged along a path that defines a circle. 4.The patella bone plate as recited in claim 3, wherein the fixation holesdefine respective central axes that lie on the circle.
 5. The patellabone plate as recited in claim 3, wherein a geometric center of thefixation hub define a center of the circle.
 6. The patella bone plate asrecited in claim 5, wherein a fixation hole at the geometric center andthe fixation holes of the array of fixation holes constitute all of thefixation holes of the hub.
 7. The patella bone plate as recited in claim5, further comprising a plurality of apertures that extend through thehub at a location radially inward with respect to the array of fixationholes.
 8. The patella bone plate as recited in claim 7, wherein theapertures are elongate along a respective central axis, and the centralaxes of the apertures define tangents of a common circle.
 9. The patellabone plate as recited in claim 3, wherein the array is a first array,and the fixation hub further comprises a second array of fixation holesthat is disposed radially outward with respect to the first array. 10.The patella bone plate as recited in claim 9, wherein the medial leg andthe lateral leg extend out from respective eyelets that define adjacentones of the fixation holes of the second array.
 11. The patella boneplate as recited in claim 10, wherein the inferior leg extends out froma respective one of the fixation nodes that is between the adjacent onesof the fixation holes of the second array.
 12. The patella bone plate asrecited in claim 1, further comprising at least one arm that extend fromthe hub to a fixation node of the plurality of fixation nodes, whereinthe at least one arm is deformable.
 13. The patella bone plate asrecited in claim 12, wherein the inner surface at the at least one armis recessed toward the outer surface with respect to the inner surfaceat each of the fixation node and the fixation hub.
 14. A patella boneplate comprising: a fixation body including: a fixation hub having aninner surface configured to face a patella bone and an outer surfaceopposite the inner surface, a first array of fixation holes that extendthrough the fixation hub from the inner surface to the outer surface,and a second array of fixation holes that is disposed radially outwardwith respect to the first array, wherein adjacent fixation holes of thefixation holes of the second array are spaced equidistantly from eachother; and a plurality of fixation nodes that extend from the fixationhub, each of the plurality of fixation nodes defining a respectivefixation hole, wherein the fixation body defines a plurality ofapertures that extend through the fixation hub from the outer surface tothe inner surface, wherein the apertures are elongate along a centralaxis.
 15. The patella bone plate as recited in claim 14, wherein thecentral axes of the apertures are tangential to a common circle that iscentered about a geometric center of the hub.
 16. The patella bone plateas recited in claim 14, wherein the fixation holes of the second arrayare alternatingly arranged with the fixation holes of the first array.17. The patella bone plate as recited in claim 14, wherein the centralaxes of the apertures are coincident with a respective straight linethat extends from a central axis of the hub to a central hole axis of analigned one of the fixation holes of the second array.